With recent developments of a networking technology, a grid computing technology for performing a calculation, which requires a huge calculation resource, using an unspecified number of computers in parallel (see Non-Patent Document 1) is now drawing attention. For example, this grid computing technology is effectively applied to the field of science and technology calculation such as clarification of gene information.
Consider, M. Ben-Or, S. Goldwasser, and A. Wigderson. Completeness theorems for non-cryptographic fault-tolerant distributed computation. In Proceedings of the 20th Annual ACM Symposium on Theory of Computing, STOC'88, pages 1-10, Chicago, Ill. USA, May 2-4, 1988. ACM.
However, with the grid computing technology, a device requesting calculation has to send a parameter necessary for the calculation to an unspecified number of computers. This allows an administrator or the like of a computer handling the calculation to read out the parameter. And this also allows one to read out the parameter by intercepting the communication line. This is why the grid computing technology cannot be applied to highly confidential calculation such as calculation of a financial risk for an inventor.
A secret calculation technology for keeping a calculation result confidential by performing a necessary calculation along with an unnecessary calculation and using only the result of the necessary calculation has been used. However, this technology cannot keep a parameter confidential nor effectively use a calculation resource due to the unnecessary calculation.